Habitats Directive Review of Consents

drives abstracted water reduction

Case Study: Cadbury’s

Summary Source Application Constraint Response Savings

River Lugg • Vacuum pump

system

• Habitats

Directive

Review of

Consents

• Summer flow

constraint

• Some switching to borehole

water

• General management

improvements

• Proposed new electric pump

system as part of US

$5million investment

• Abstraction of river

water reduced from

over 5,000 m3 per day

to under 4,000 m3 per

day

• Further water savings

of up to 75%, if new

investment proceeds

Company overview

The Cadbury factory at Marlbrook, Herefordshire, processes fresh milk, sugar and cocoa liquor to

produce chocolate ‘crumb’ – the main ingredient in many of Cadbury’s milk chocolate products. The

‘crumb’ is then blended with cocoa butter, refined and turned into milk chocolate at other factories.

For the past 17 years, Cadbury has operated Environmental Management Systems to ensure the

environmental impact of its operations is minimised. More recently, Cadbury has demonstrated its

ongoing commitment to high standards of environmental protection through ‘Purple Goes Green’,

initiative which targets ambitious reductions in the use of resources, including water and energy. In

early 2010, Cadbury became part of the international company Kraft Foods.

Figure 1: Cadbury’s Marlbrook site is situated on the River Lugg

Process overview

Fresh full-cream milk is brought to the Marlbrook site where it is mixed with sugar and then

condensed into a thick liquor through the process of evaporation. The liquor passes through the

system via a series of vacuum pumps and is then mixed with cocoa liquor produced at the Cadbury

plant in Chirk, North Wales. The mixture is cooked and kneaded to the correct consistency before

being dried in large vacuum ovens to produce the final milk chocolate ‘crumb’ (Figure 2).

Figure 2: Illustration of the process at the Marlbrook site.

The production process at Marlbrook is continuous with some seasonal flexibility, for example

production typically increases in the lead up to the Easter and Christmas periods.

The site has 11 process lines (of which 10 are operational and one is offline for cleaning at any one

time) with a capacity to process over 500,000 litres of milk per day, producing 93,000 tonnes of milk

chocolate ‘crumb’ per year. In general, the site operates 5 shifts of 10 operators to maintain

production for 24 hours per day, 365 days per year. The site also has the capacity to store up to

3,000 tonnes of ‘crumb’.

Water use overview

Nearly all of Cadbury’s water is abstracted from river and groundwater sources. Water is drawn from

three boreholes which, along with recovered milk condensate, supply all of the process water used

on site and for vessel cleaning. Water from the River Lugg is used within the vacuum pump system to

create the vacuums required within the cooking and drying vessels and to pump the liquid around

the process. It is used on a ‘once through’ basis and is returned approximately 100m downstream

after passing through a series of on-site cooling lagoons. During winter months, it would be possible

to recirculate water from the cooling lagoons, although during the rest of the year ambient

temperatures make this more difficult. In discussion with local regulators, the view has been that the

trade-off between higher return temperatures and abstraction volumes favours continued

abstraction rather than re-use.

Temperatures are monitored in the cooling ponds to ensure that water is returned at an appropriate

temperature and the chemical properties of the discharges are similarly controlled so that waste

cleaning water is separated from solids and limited chemical treatment is undertaken.

As the milk is evaporated, the water vapour is condensed, collected and re used. This means that

more water is returned to the River Lugg than is abstracted both from groundwater and from the

river, and the product itself contains less water at the end of the process than at the beginning.

Cadbury’s currently has a licence to abstract around 6,500 m3 per day from the River Lugg and a

permit allowing the discharge of 5,500m3 per day back to the river, although a typical daily average

discharge is around 4,500m3 and, in general, the plant is a net contributor of water to the river. The

site generates around 600-750m3 of wastewater per day which is discharged back to river following

dewatering. The resulting sludge is removed from the site as solid waste. Abstractions at the site are

governed by three licences, as set out in Table 1.

Table 1: Summary of abstraction licences at the Marlbrook site.

Consent Description Maximum

volume per hour

Daily and annual

limits

19/55/12/827 Boreholes

1

2

18.18 m3

27.28 m3

1+2 combined

416 m3 in any day

151,840 m3

in any

year

19/55/12/53 River Lugg 272.8 m3 6,532.6 m

3 per day

2,384,399 m3 per

year

19/55/12/82 Borehole 3 6,000 gallons 52,800 gallons per

day

= 19,272,000

gallons per year

Restated as m3 27.28 m

3 240 m

3 per day

87,611 m3 per year

The costs of abstraction from borehole and river water consist of the pumping costs, which are fuel-

cost dependent, and the cost of maintaining the abstraction and discharge consents. Abstraction

licensing currently costs around £3,500 per year. Table 2 provides an overview of the site’s

abstraction over the last eight years from the two sources. During the last five years, production at

the site has remained virtually constant at approximately 82,000 tonnes of product.

Table 2: Water consumption at the Marlbrook site.

Trends in water use

Year Parameter

Groundwater

(Average m3/day)

River water

(Average

m3/day)

Total

(Average

m3/day)

2002 240 7,497 7,737

2003 84 5,444 5,528

2004 215 5,691 5,906

2005

183 5,744 5,927

2006

200 4,912 5,112

2007 497 4,442 4,939

2008 534 4,135 4,669

2009 563 4,592 5,155

2010

722 3,851 4,573

Average % of

total

7% 93% 100%

Constraints on water use

The River Lugg is situated within the River Wye catchment area. According to the Environment

Agency’s Catchment Abstraction Management Strategy, the majority of rivers within the catchment

are of considerable ecological value, providing important and diverse habitats and key breeding

areas for many nationally and internationally important species. As such the international

importance of the catchment has been recognised through the designation of the River Wye and

some of its tributaries as a riverine Special Area of Conservation (SAC) under the European Union

(EU) Habitats Directive (1992).

Further to this, the ‘resource availability status’ for the River Lugg is classed as ‘no available water’

and the Environment Agency (EA) proposes to restrict abstractions by 20% during the summer

months.

The river abstraction limits for Cadbury are, in the most part, suitable for its requirements. The

company has a daily consent (currently set at 6,353m3), which during 2002, 2003 and 2004 was

frequently exceeded. However, measures put in place in 2004/5, combined with increased

abstraction from boreholes, have largely overcome this problem with a decrease in average daily

river water demand to around 4,000m3 and no incidents of exceeding the limit for river abstraction

recorded in 2008, 2009 or 2010 (Figure 3). However, this has led to over abstraction from their

licensed boreholes on site (Figure 3).

Following discussions with the Environment Agency regarding the amendment of two of their

abstraction licences under the Habitats Directive Review of Consents (HD RoC), Cadbury’s set out

their future plans to improve their evaporative cooling system (see below) to ensure that they

remain within their licensed limits. They are also developing a longer term plan to reduce water

usage on site by a minimum of 3% per annum.

Groundwater is abstracted by Cadbury from three boreholes within the same aquifer via on-site

pumping stations (Figure 4). This water is primarily used in the cleaning of vessels and process

equipment.

Figure 4: Pumping station for Borehole 2

Abstraction limits are placed on the three groundwater sources as outlined in Table 1. Currently,

only a small proportion of the company’s water supply is taken from the town’s supply and used for

domestic purposes, including in the canteen and staff facilities.

Exploration of technology At present, Cadbury deploys a series of vacuum pumps which work by injecting steam into a piston

causing the piston to expand, followed by a jet of cold water causing the steam to condense and the

piston to contract. Water is used for both the steam injection and cooling cycles of the piston’s

action. Borehole water is used to condense the vapour in the evaporators.

The plant currently uses electric pumps with a liquid ring main. The next progressive step would be

to use a ‘dry’ centralised vacuum system. The proposed upgrade would see the replacement of this

system with more modern electric pumps, thereby reducing water demand considerably.

In 2008/9, on-site improvements were undertaken which further reduced surface water extraction

(with an increase in abstraction from groundwater sources), but these were largely either

management and process improvements, or a consequence of changes carried out for production

and efficiency purposes which also improved environmental performance.

Going forward, there are plans for further capital investment in the plant which will both improve

production and reduce surface water abstractions in two phases:

• Phase 1 will include consolidation of the dairy facility;

• Phase 2 will include the establishment of a new evaporator unit at a cost of approximately

US $5million. The evaporator unit will recover more water from the milk than is currently

retained and it is anticipated that this will considerably reduce abstracted water use and cut

maintenance costs. Part of this investment will also include the renewal of dated process

equipment which will reduce stoppages, thereby contributing to an overall increase in the

efficiency of the process.

A capital investment of over US $5million is proposed over a number of years, depending on the

availability and release of funds. Within Cadbury, the case for investment is usually based either on

financial benefit or legislative requirements. As it is difficult to achieve financial benefits, owing to

the low cost (including energy costs) of abstracted water, it is often legislative requirements that

drive improvement within the organisation.

The case for investment in the plant is largely tied to the ongoing viability of the plant and the

suitability of its location for continued production. Securing funds at a corporate level involves an

investment appraisal and competition with other demands on corporate capital. Separating out the

costs related to reducing water use from the overall improvements in both production and

environmental quality is not possible. However, given Cadbury’s high public profile, the perception is

that the risks to its reputation and the opportunities associated with good environmental

performance encourage considerably more investment in environmental technologies than might be

warranted by the financial case alone. This has meant that making the case for capital investment at

a corporate level is enhanced by environmental improvements, such that the planned improvements

being proposed for commercial purposes can also incorporate considerable environmental

improvement even where that has an impact on capital costs.

While environmental improvements may not themselves be a direct driver of new investment, they

do appear to influence the design of new plant and capital allocation decisions.